Pick a universe, any universe. How many hypothetical universes
would support life?

Possibly only one, say the authors of a new study. Published
in the July issue of Science, the report says that if the physical
forces within stars were only slightly different, our universe would be almost
devoid of carbon and oxygen, and life would not exist.

The findings bring scientists face to face with the question
of design. "I am not a religious person, but I could say this universe is
designed very well for the existence of life," said Heinz Oberhummer, astrophysicist
at the University of Vienna, Austria.

Mr. Oberhummer and his colleagues used computers to simulate
the process by which helium burns to produce carbon and oxygen during the
red-giant stage of a star's life. They found that even slight changes in either
the strong or weak nuclear force would destroy nearly all the carbon or oxygen
inside stars-making life impossible.

"The basic forces in the universe are tailor-made for the production of ...
carbon-based life," Mr. Oberhummer told Space.com.

It's a new day when scientists who are not "religious persons"
are compelled to use the language of design. Mr. Oberhummer's discovery adds
to the enormous number of "cosmic coincidences" uncovered by cosmology--intricate
balances among the universe's fundamental forces. For example, if the force
of gravity were only slightly stronger, all stars would be red dwarfs, too
cold to support life. If it were slightly weaker, all stars would be blue
giants, burning too briefly for life to develop.

In the atom, the mass of the neutron is delicately balanced
with that of the proton; otherwise, protons would decay into neutrons, making
life impossible.

"Imagine a universe-creating machine, with thousands of dials
representing the gravitational constant, the charge on the electron, the mass
of the proton, and so on," said Steve Meyer of Whitworth College. "Each dial
has many possible settings, and even the slightest change would make a universe
where life was impossible." Yet each dial is set to the exact value needed
to sustain life-for no known reason.

As Mr. Oberhummer put it, "we have no idea why the strengths
of the forces are fine-tuned" to support life. The reasonable answer seems
to be that someone intended it that way.

To avoid that surprising conclusion, cosmologists are scrambling
to craft alternative explanations. Some adopt the "many worlds" hypothesis,
suggesting that there exist an infinite number of universes. Most would be
dark and lifeless, but by sheer probability a few might be suitable for life--and
we happen to live in one.

How do scientists account for these zillions of universes? Some
say mini-universes crowd together within a larger universe like bubbles in
foam. Others propose an oscillating universe--continually expanding, collapsing,
then expanding again to form new universes with different physical laws. Strangest
by far is physicist Hugh Everett's notion that all possible states of a quantum
interaction are actualized, so that slightly different versions of our universe
are constantly splitting off--creating a near-infinitude of new universes
at every moment.

What's the evidence for these other universes? There is
none. By definition, they cannot be observed. Nor has anyone offered a plausible
scientific explanation for how they arise. "There is no hint as to what causal
mechanism would produce such a splitting," complained philosopher John Earman--which
renders it akin to a "miracle."

Moreover, the hypothesis violates the principle of simplicity.
As Guillermo Gonzalez of the University of Washington told World, "Invoking
an infinitude of unobservable universes to explain the one observable universe
is a grotesque violation of Occam's razor," the principle that entities should
not be multiplied unnecessarily.

Other cosmologists try to explain design by a quasi-pantheistic
philosophy that attributes intelligence and foresight to the universe itself.
In The Fifth Miracle, Paul Davies says, "the laws of the universe are
cunningly contrived to coax life into being"; they "somehow know in advance
about life and its vast complexity." This year's Templeton prize-winner, Freeman
Dyson, muses that "the universe in some sense must have known we were coming."

Of course, the idea of a conscious universe, or of unknowable
universes sprouting like mushrooms, goes beyond science and into philosophy.
This opens a new opportunity for Christians, says philosopher William Lane
Craig. "Cosmology has broken down the boundary between physics and metaphysics,"
he told World. "And once the door is opened to metaphysics, you can't
stop the theist from coming in the door, too."

If the universe appears "tailor-made" for life, perhaps the
simplest explanation is that it was tailor-made.